CN217334362U

CN217334362U - End cover, end cover assembly, battery monomer, battery and power consumption device

Info

Publication number: CN217334362U
Application number: CN202221530904.1U
Authority: CN
Inventors: 尚志同; 温耀铃
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-08-30
Anticipated expiration: 2032-06-20
Also published as: WO2023245819A1

Abstract

The application relates to an end cover, an end cover assembly, a single battery and an electric device, wherein the cover body is provided with a liquid injection hole penetrating through two sides of the thickness direction of the cover body, the liquid injection hole comprises a first hole section and a second hole section which are arranged from top to bottom along the thickness direction of the cover body, and the first hole section and the second hole section are communicated with two ends close to each other. The first hole section is used for accommodating the liquid injection nozzle, at least part of hole wall is attached to the outer wall of the liquid injection nozzle and forms an anti-overflow area, and the anti-overflow area is positioned above the liquid injection port of the liquid injection nozzle. In this application, annotate inside the smooth and easy flow direction battery monomer of liquid mouth outflow's whole electrolyte through second hole section, and can not remain in annotating the liquid downthehole, can avoid because of annotating the downthehole gasification of remaining electrolyte and lead to sealed nail splice to have welding defect, and then avoid annotating the problem that liquid hole sealing reliability descends because of welding defect causes.

Description

End cover, end cover assembly, battery monomer, battery and power consumption device

Technical Field

The application relates to the technical field of battery manufacturing, in particular to an end cover, an end cover assembly, a battery monomer, a battery and an electric device.

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry, and electric vehicles become important components of the sustainable development of the automobile industry due to the advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

In the battery technology, in order to conveniently inject the electrolyte into the battery cell, an end cap of the battery cell is generally provided with an injection hole which is through from top to bottom, and the injection hole is sealed by a sealing nail after the electrolyte is injected. The existing battery has the problem of low sealing reliability of the liquid injection hole.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present application provides an end cap, an end cap assembly, a battery cell, a battery, and an electric device, which can solve the problem of low sealing reliability of a liquid injection hole.

In a first aspect, the present application provides an end cap for a battery cell, the end cap including a cap body having a liquid injection hole running through both sides of its thickness direction, the liquid injection hole including a first hole section and a second hole section opened from top to bottom along the thickness direction of the cap body, the first hole section and the second hole section communicating at both ends close to each other. The first hole section is used for accommodating the liquid injection nozzle, at least part of hole wall is attached to the outer wall of the liquid injection nozzle and forms an anti-overflow area, and the anti-overflow area is positioned above the liquid injection port of the liquid injection nozzle.

Among the technical scheme of this application embodiment, the electrolyte that flows from annotating the liquid mouth is kept off in the below and can not spill over outside the anti-overflow district by anti-overflow district is whole, can make from this that the whole electrolyte that flows through annotating the liquid mouth flows inside through the smooth and easy flow direction battery monomer of second hole section, and can not remain in annotating the liquid hole. Therefore, the welding defect of the welding position of the sealing nail caused by the gasification of the residual electrolyte in the liquid injection hole can be avoided, and the problem of the reduction of the sealing reliability of the liquid injection hole caused by the welding defect can be further avoided.

In some embodiments, the wall of the first bore section is fully engaged with the outer wall of the pouring spout, and the pouring opening of the pouring spout extends into the second bore section. At the moment, the overflow-proof area formed by the first hole section and the liquid injection nozzle is larger, and the overflow-proof effect is good. And, annotate the notes liquid mouth of liquid mouth and directly stretch into the second hole section in, electrolyte directly gets into the second hole section from annotating the liquid mouth and discharging back, can shorten electrolyte and get into the inside distance of battery monomer, can avoid electrolyte to remain on the pore wall of first hole section simultaneously.

In some embodiments, the aperture diameter of the first hole section is gradually reduced from top to bottom, and the aperture diameter of the end of the second hole section connected with the first hole section is equal to or larger than the minimum aperture diameter of the first hole section. At this moment, when the aperture of first hole section reduces gradually from top to bottom, can not form circuitous structure, electrolyte can be smooth and easy flow down under the dead weight, and can directly flow towards the battery monomer inside from the electrolyte of first hole section flow direction second hole section, can reduce the probability that electrolyte flows along the pore wall of second hole section, improves the injection efficiency of electrolyte.

In some embodiments, the pour spout further includes a third hole segment, and the first hole segment communicates between the third hole segment and the second hole segment. The aperture of the end of the third hole section connected with the first hole section is equal to or larger than the maximum aperture of the first hole section. At this moment, when carrying out the secondary seal to annotating the liquid hole, can hold the second sealing member in third hole section, can avoid the second sealing member to expose outside the lid, it is also easy to cause the scratch to the external world to be unsightly promptly.

In some embodiments, the angle between the wall of the first hole section and the thickness direction of the cover body is a first angle alpha, wherein alpha is more than or equal to 0 degrees and less than or equal to 45 degrees. At the moment, the hole wall of the first hole section is an inclined straight wall, and machining is facilitated. Meanwhile, the first included angle alpha is in the range of 0-45 degrees, the resistance of the hole wall of the first hole section to the electrolyte is small, the electrolyte entering the first hole section conveniently flows to the second hole section smoothly under the self-weight, and the electrolyte is prevented from being stuck on the hole wall of the first hole section.

In some embodiments, the cover body comprises a cover part and a liquid injection platform, the liquid injection platform is convexly arranged on a structural surface of the cover part, which is far away from the inner part of the battery unit, and the liquid injection hole penetrates through the cover part and the liquid injection platform. At the moment, the liquid injection platform is convexly arranged on the cover part, so that the length of the liquid injection hole can be prolonged, the matching area of the first sealing piece and the liquid injection hole is increased, the effectiveness of primary sealing and the installation stability of the first sealing piece are improved, meanwhile, the second sealing piece and the liquid injection platform can be bent to contact to form a circuitous path, and the sealing reliability and the sealing effect of the liquid injection hole are improved.

In some embodiments, the liquid injection platform is configured with a bead groove recessed toward the liquid injection hole on an outer circumferential side wall disposed around the axial direction of the liquid injection hole. At the moment, the second sealing element can be in sealing connection with the groove wall, part of the peripheral side wall and all end walls of the hemming groove, the sealing area of the liquid injection platform and the second sealing element is greatly improved, and meanwhile, the sealing effect of the second sealing element is improved through a circuitous route formed by the hemming groove, the peripheral side wall and the end walls. Moreover, the arrangement of the crimping groove can also strengthen the fixation between the second sealing element and the liquid injection platform.

In some embodiments, a side inner wall of the crimping groove in the thickness direction and disposed near the inside of the battery cell is a first wall surface, and the first wall surface is flush with the structural surface. At the moment, the hemming groove can be formed by the convex plate arranged on the peripheral side wall of the liquid injection platform and the structural surface together, grooving and the like are not needed, and the hemming groove is more convenient to form.

In some embodiments, the cover portion is configured with an avoidance groove recessed toward the inside of the battery cell, and a bottom surface of the avoidance groove serves as a configuration surface. The protruding height of the liquid injection platform can be reduced by the arrangement of the avoiding groove, and even the liquid injection platform is not protruded, so that the influence of the liquid injection platform on the outside can be reduced, and the liquid injection platform can be prevented from being damaged by the outside. Meanwhile, when the second sealing element is bent, the avoidance groove can provide a larger operation space.

In some embodiments, the recess depth of the hem groove is a first dimension D1, the width of the hem groove in the thickness direction is a second dimension D2, and the distance between the bottom of the hem groove and the side wall of the avoidance groove disposed opposite the bottom of the hem groove in the direction perpendicular to the thickness direction is a third dimension D3. Wherein D1 is more than or equal to 0.5mm, D2 is more than or equal to 0.5mm, 2 is more than or equal to D1/D2 is more than or equal to 0.5, and D3 is more than or equal to 3D 1. It is proved by experiments that when the first dimension D1, the second dimension D2, and the third dimension D3 are within the above-mentioned range, a space for performing a crimping operation is large when the second sealing member is crimped, thereby facilitating the crimping operation of the second sealing member.

In some embodiments, the end cap further includes a baffle plate disposed on a side of the cover body facing the inside of the battery cell and blocking a flow path of the electrolyte flowing from the electrolyte injection hole directly to the inside of the battery cell. The baffle can prevent the fast flowing electrolyte from directly impacting on the electrode assembly to damage the electrode assembly.

In a second aspect, the present application provides an end cap assembly for a battery cell, the end cap assembly comprising a first sealing member, a second sealing member and an end cap as provided in any of the above embodiments. The first sealing element is arranged in the liquid injection hole and blocks the first hole section and the second hole section, and the second sealing element covers one side of the first sealing element, which is far away from the interior of the battery monomer, and is connected with the cover body in a sealing mode.

In the technical scheme of this application, because annotate liquid hole structure formation and can make electrolyte accessible flow to the inside structure of battery monomer, electrolyte can not remain basically in annotating the liquid hole, so when carrying out the secondary seal to annotating the liquid hole, can not lead to welding defect's appearance because of the electrolyte penetration molten bath of gasification when welding the second sealing member, and then can avoid annotating the problem that liquid hole seal reliability reduces because of welding defect causes.

In some embodiments, the cover body comprises a cover part and a liquid injection platform, the liquid injection platform is convexly arranged on a structural surface of the cover part, which is far away from the inner part of the battery unit, and the liquid injection hole penetrates through the cover part and the liquid injection hole. The second sealing piece is provided with a first sealing part and a second sealing part which are connected, the first sealing part covers one side, deviating from the interior of the battery monomer, of the first sealing piece, and the second sealing part is bent towards the interior of the battery monomer relative to the first sealing part and is connected with the peripheral side wall of the liquid injection platform in a sealing mode. Therefore, the second sealing element performs secondary sealing through the first sealing part and the second sealing part, the sealing area is large, and the sealing effect is good. Meanwhile, the first sealing part and the second sealing part are bent to form a roundabout sealing path, so that the sealing effect is further improved.

In some embodiments, the liquid injection platform is configured with a bead groove recessed toward the liquid injection hole on an outer circumferential side wall disposed around the axial direction of the liquid injection hole. Wherein, the second sealing includes continuous first crimping section and second crimping section, and first sealing is connected to first crimping section, and relative first sealing buckles towards battery monomer inside and sets up, first crimping section and the peripheral lateral wall sealing connection who annotates the liquid platform, and relative first crimping section of second crimping section is buckled towards annotating the liquid hole and is set up and sealing connection in crimping inslot. At the moment, the second sealing element can be in sealing connection with the groove wall, part of the peripheral side wall and all the end walls of the crimping groove, the sealing area of the liquid injection platform and the second sealing element is greatly increased, and meanwhile, the sealing effect of the second sealing element is improved through a circuitous route formed by the crimping groove, the peripheral side wall and the end walls. Moreover, the hook-shaped structure formed by the first sealing part, the first curling section and the second curling section can further strengthen the fixation between the second sealing element and the liquid injection platform.

In some embodiments, the second sealing member includes a heat-fusible layer and a heat-conductive layer, the heat-fusible layer is located between the heat-conductive layer and the cover, and the heat-fusible layer is configured to be fused by heat to hermetically connect the heat-conductive layer and the cover. At this moment, the heat conduction layer and the liquid injection platform (and/or the first sealing element) are bonded by the hot melting layer, and the hot melting temperature is far lower than the high temperature generated during welding, so that the gasification of the electrolyte can be relieved or even avoided, and the problems that the bonding strength is reduced and the sealing effect is influenced because the gasified electrolyte penetrates through the hot melting layer can be avoided.

In some embodiments, the first sealing member includes a main body portion and a positioning portion, the main body portion and the positioning portion are abutted in the thickness direction, the main body portion is in sealing fit with the liquid injection hole, and the positioning portion is located outside the liquid injection hole and is overlapped on the surface of the cover body, which faces away from the interior of the battery cell. The second sealing element is hermetically covered on the positioning part. So, can judge whether first sealing member is installed in place according to whether location portion overlaps with the lid for the installation of first sealing member is more convenient.

In some embodiments, the first sealing member further includes a position-limiting portion located outside the liquid injection hole, the main body portion is connected between the position-limiting portion and the positioning portion, and the position-limiting portion abuts against a surface of the cover body facing the inside of the battery cell. After the first sealing element is installed in place, the first sealing element is limited on the cover body through the positioning part and the limiting part, and the first sealing element can be effectively prevented from falling off.

In a third aspect, the present application provides a battery cell, which includes a casing, an electrode assembly, and the end cap assembly in any of the above embodiments, where the casing encloses a receiving cavity with an opening, the electrode assembly is received in the receiving cavity, and the end cap covers the opening.

In a fourth aspect, the present application provides a battery including the battery cell of the above embodiment.

In a fifth aspect, the present application provides an electric device, which includes the battery in the above embodiments, and the battery is used for providing electric energy.

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Moreover, like reference numerals are used to refer to like elements throughout. In the drawings:

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

FIG. 2 is an exploded schematic view of a battery in some embodiments of the present application;

fig. 3 is an exploded view of a battery cell in some embodiments of the present application;

FIG. 4 is a schematic structural view of an end cap according to some embodiments of the present application;

FIG. 5 is a cross-sectional view of the end cap shown in FIG. 4;

FIG. 6 is a schematic illustration of a pouring spout used with an end cap according to some embodiments of the present application;

FIG. 7 is a partial cross-sectional view of a cover according to some embodiments of the present application;

FIG. 8 is a schematic view of an end cap in a fluid-filled state according to some embodiments of the present application;

FIG. 9 is a schematic view of an end cap in a primed state according to further embodiments of the present application;

FIG. 10 is a partial end view of a cover in accordance with certain embodiments of the present application;

FIG. 11 is an assembly view of a cover and a first seal member according to some embodiments of the present application;

FIG. 12 is an assembly view of the cap with the first and second seal members in accordance with certain embodiments of the present disclosure;

FIG. 13 is a schematic view of a first seal according to some embodiments of the present disclosure;

FIG. 14 is a state diagram of a second seal according to some embodiments of the present application;

FIG. 15 is an exploded view of an end cap according to some embodiments of the present application.

The reference numbers in the detailed description are as follows:

1000. a vehicle; 100. a battery; 200. a controller; 300. a motor; 10. a box body; 11. a first portion; 12. a second portion; 20. a battery cell; 21. an end cap assembly; 21a, an end cover; a1, a cover body; a11, a cover; s, structural plane; p, avoiding the groove; a12, liquid injection platform; w, a peripheral sidewall; h. a hemming groove; r, a first avoidance surface; k. a liquid injection hole; k1, a first bore section; k2, a second bore section; k3, third bore section; a2, baffle; f. a buffer space; 21b, a first seal; b1, a main body part; b2, a positioning part; b3, a limiting part; 21c, a second seal; c1, a first seal; c2, a second seal; c21, a first crimping section; c22, a second hemming section; c3, hot melt layer; c4, a heat conducting layer; 21d, electrode terminals; 21e, an insulating member; 22. a housing; 23. an electrode assembly; 400. a liquid injection nozzle; 401. a flow channel; 403. a liquid injection port; 402. a mating surface; F. the thickness direction.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or to implicitly indicate the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural pieces" refers to two or more (including two).

In the description of the embodiments of the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships that are based on the orientations and positional relationships shown in the drawings, and are used for convenience in describing the embodiments of the present application and for simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used in a broad sense, and for example, may be fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. Specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

The battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace.

The inventor has noted that, in order to conveniently inject the electrolyte into the battery cell through the injection hole, the injection hole is usually designed to be a step, the injection hole of the injection nozzle is supported at the step, and after the injection is completed, the electrolyte is easily remained at the step of the injection hole. The electrolyte remaining at the corners of the step is generally not removed effectively. After annotating the liquid completion, carry out once sealed back (filling in the sealing member in annotating the liquid hole) to annotating the liquid hole and usually can carry out the secondary at another sealing member of the outside laser welding of annotating the liquid hole and seal, because remaining electrolyte of step corner under the high temperature environment that laser welding produced, gasify easily and rush out the molten bath and cause welding defects such as pinhole, explosion point, lead to annotating liquid hole sealing reliability and reduce.

In order to solve the problem of reliability of the sealing of the liquid filling hole, the applicant researches and discovers that the problem of reliability reduction of the sealing of the liquid filling hole caused by the electrolyte can be solved by avoiding the electrolyte from remaining in the liquid filling hole. Specifically, design electrolyte can accessible intercommunication in annotating the downthehole structure of annotating for enter into annotate downthehole electrolyte can accessible all flow into inside the battery monomer, and can not remain in annotating the liquid downthehole.

Based on above consideration, in order to solve the problem that annotate liquid hole seal reliability is low, the inventor is through deep research, an end cover has been designed, annotate liquid hole on the end cover and include first hole section and the second hole section that top-down seted up, the both ends intercommunication that two hole sections are close to each other, annotate the pore wall laminating of liquid mouth and first hole section simultaneously, avoid electrolyte to overflow away through first hole section, consequently can make whole electrolyte enter into inside the battery monomer via the second hole section, alleviate the problem that annotate liquid hole seal reliability that causes seal nail welding defect and lead to reduces because of electrolyte remains.

The end cover disclosed by the embodiment of the application can be used for preparing a battery cell. The battery cell disclosed in the embodiment of the present application can be used in, but not limited to, an electric device for a vehicle, a ship, an aircraft, or the like. The power supply system who possesses this power consumption device of constitution such as battery monomer, battery that this application is disclosed can be used, like this, is favorable to alleviating and automatically regulated electric core bulging force worsens, and supplementary electrolyte consumes, promotes the stability and the battery life of battery performance.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments take an example in which a power consuming apparatus according to an embodiment of the present application is a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, and for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in addition to fuel or natural gas, to provide driving power to the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cells 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with one open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the case 10 formed by the first and

second portions

11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 20. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and the whole is accommodated in the box 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 refers to the smallest unit constituting the battery. As shown in fig. 3, the battery cell 20 includes an end cap assembly 21, a case 22, an electrode assembly 23, and other functional components.

The end cap assembly 21 refers to a member that covers an opening of the case 22 to insulate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap assembly 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap assembly 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap assembly 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength, and the safety performance may be improved. The end cap assembly 21 may be provided with functional components such as the electrode terminals 21 d. The electrode terminal 21d may be used to electrically connect with the electrode assembly 23 for outputting or inputting electric energy of the battery cell 20. In some embodiments, a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value may be further disposed on the end cap assembly 21. The material of the end cap assembly 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in this embodiment. In some embodiments, insulation may also be provided on the inside of the end cap assembly 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap assembly 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The case 22 is an assembly for mating with the cap assembly 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap assembly 21 may be separate components, and an opening may be provided in the housing 22, and the opening may be covered by the end cap assembly 21 to form the internal environment of the battery cell 20. Without limitation, the end cap assembly 21 and the housing 22 may be integrated, and specifically, the end cap assembly 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is required to enclose the inside of the housing 22, the end cap assembly 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention.

The electrode assembly 23 is a part in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 may be contained within the case 22. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally disposed between the positive electrode sheet and the negative electrode sheet. The sealing parts of the positive and negative electrode tabs having the active material constitute the body parts of the electrode assembly, and the sealing parts of the positive and negative electrode tabs having no active material each constitute a tab. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected with the electrode terminals to form a current loop.

Fig. 4 is a schematic structural view of an end cap 21a according to some embodiments of the present application, and fig. 5 is a cross-sectional view of the end cap 21a shown in fig. 4. According to some embodiments of the present application, referring to fig. 4 and 5, an end cap 21a for a battery 100 is provided, the end cap 21a includes a cover body a1, the cover body a1 has a liquid injection hole k penetrating through both sides of the cover body a1 in a thickness direction F, the liquid injection hole k includes a first hole section k1 and a second hole section k2 which are opened from top to bottom in the thickness direction F of the cover body a1, and both ends of the first hole section k1 and the second hole section k2 are communicated with each other. Wherein the first hole section k1 is used for accommodating the liquid filling nozzle 400, and at least part of the hole wall is jointed with the outer wall of the liquid filling nozzle 400 and is constructed to form an anti-overflow area which is positioned above the liquid filling opening 403 in the liquid filling nozzle 400.

The cap a1 is a structure that can form a sealed space accommodating the electrode assembly 23 together with the case 22 of the battery cell 20. The liquid injection hole k is formed in the lid body a1 to communicate the inside and the outside of the battery cell 20, so that the external electrolyte can be injected into the battery cell 20. The lid a1 may be plate-shaped, block-shaped, or the like, and is not particularly limited.

In actual use, the thickness direction F of the lid body a1 corresponds to the vertical direction. The first hole section k1 and the second hole section k2 are opened from top to bottom, that is, the first hole section k1 is communicated above the second hole section k 2. The first hole section k1 and the second hole section k2 may be coaxially arranged, or may be eccentrically arranged, and for convenience of description, the first hole section k1 and the second hole section k2 are coaxially arranged, that is, the liquid injection hole k is provided with a central axis disposed in the thickness direction F.

FIG. 6 is a schematic illustration of a pouring spout 400 for use with end cap 21a in some embodiments of the present application. Referring to FIG. 6, the pouring nozzle 400 is a member that can be connected to an electrolyte supply source and has a pouring port 403 through which the electrolyte flows from the inside of the pouring nozzle 400 into the pouring hole k, the pouring port 403 is an output position of the pouring nozzle 400 to communicate the inside of the pouring nozzle 400 with the poured liquid, a flow path 401 is formed in the pouring nozzle 400 to communicate the electrolyte supply source with the pouring hole k, and the pouring port 403 is located at the outlet of the flow path 401.

In the actual pouring operation, the pouring nozzle 400 is at least partially accommodated in the first hole section k1, and the pouring nozzle 400 is fitted with at least part of the hole wall of the first hole section k1 to form a spill-proof zone, and the pouring outlet 403 of the pouring nozzle 400 is located below the spill-proof zone.

Understandably, the hole wall of the first hole section k1, which is attached to the liquid injection nozzle 400, is continuously arranged around the central axis of the liquid injection hole k, so that the liquid injection nozzle 400 and the hole wall attached to the liquid injection nozzle can be hermetically connected to form an anti-overflow area, and the electrolyte flowing out of the liquid injection port 403 is prevented from flowing upwards from the gap between the liquid injection nozzle 400 and the hole wall and leaking out of the anti-overflow area.

The end cap 21a allows the electrolyte flowing out from the liquid pouring nozzle 400 to be completely blocked by the spill-proof area without overflowing to the outside of the spill-proof area, so that the electrolyte flowing out through the liquid pouring nozzle 400 can smoothly flow into the battery cell 20 through the second hole section k2 without remaining in the liquid pouring hole k. Therefore, the welding defect of the welding position of the sealing nail caused by the gasification of the residual electrolyte in the liquid injection hole k can be avoided, and the problem of the reduction of the sealing reliability of the liquid injection hole k caused by the welding defect can be further avoided.

In some embodiments, the aperture diameter of the end of the first bore segment k1 connecting the second bore segment k2 is less than or equal to the aperture diameter of the end of the second bore segment k2 connecting the first bore segment k 1.

Two pore walls of first pore section k1 and second pore section k2 straight connection are first pore wall and second pore wall respectively, when the aperture that first pore section k1 connects the one end of second pore section k2 is greater than the aperture that second pore section k2 connects the one end of first pore section k1, can form interior step structure between first pore wall and the second pore wall, when electrolyte flows through this interior step structure, remain in interior step structure department easily, electrolyte can not be smooth and easy from the smooth flow direction second pore section k2 of first pore section k 1. In the embodiment of the application, the aperture of the end of the first hole section k1 connected with the second hole section k2 is smaller than or equal to the aperture of the end of the second hole section k2 connected with the first hole section k1, so that the electrolyte can be prevented from being retained at the inner step, and the electrolyte can flow to the first hole section k1 from the second hole section k2 without obstacles.

In order to enable the electrolyte to flow smoothly from the first hole section k1 to the second hole section k2, the arrangement of the first hole section k1 and the second hole section k2 may exclude the following manner: when the first hole wall is perpendicular to the central axis of the liquid injection hole k, an inner step structure formed by the hole walls except the first hole wall in the first hole section k1 and the first hole wall, when the first hole wall inclines from bottom to top relative to the central axis of the liquid injection hole k, an inner step structure formed by the hole walls except the first hole wall in the first hole section k1 and the first hole wall, a groove/concave hole structure which is formed on the first hole wall and is concave from top to bottom when the first hole wall extends from top to bottom, and the like.

In order to enable the electrolyte to smoothly flow to the second hole section k2 from the first hole section k1, the hole wall of the first hole section k1 is integrally extended from top to bottom, specifically, the hole wall of the first hole section k1 may be extended from top to bottom by a straight wall/an inclined wall, or extended from top to bottom by an arc wall, or extended from top to bottom by a wave wall, so long as there is no structure for retaining the electrolyte, and the electrolyte can smoothly flow into the second hole section k2 along the hole wall of the first hole section k1 under the self weight.

At this time, the first hole section k1 can accommodate the pouring nozzle 400, and the hole wall of the first hole section k1 is jointed with the pouring nozzle 400 to form an overflow-preventing area, so that the electrolyte flowing out of the pouring nozzle 400 can directly enter the second hole section k2 or can flow into the second hole section k2 through the first hole section k1 without obstruction. Therefore, the welding defect of the welding position of the sealing nail caused by the gasification of the residual electrolyte in the injection hole k can be avoided, and the problem of the reduction of the sealing reliability of the injection hole k caused by the welding defect can be further avoided.

Fig. 7 is a partial cross-sectional view of cover a1 in some embodiments of the present application, and fig. 8 is a schematic view of end cap 21a in a liquid-filled state in some embodiments of the present application. Referring to FIGS. 7 and 8, in some embodiments, the wall of the first hole section k1 is completely attached to the outer wall of the pouring nozzle 400, and the pouring outlet 403 of the pouring nozzle 400 extends into the second hole section k 2.

The term "completely fit" means that all the hole walls of the first hole section k1 are fitted to the outer wall of the pouring nozzle 400.

At this time, the overflow-proof area formed by the first hole section k1 and the liquid injection nozzle 400 is large, and the overflow-proof effect is good. Moreover, the liquid injection port 403 of the liquid injection nozzle 400 directly extends into the second hole section k2, and the electrolyte is discharged from the liquid injection port 403 and then directly enters the second hole section k2, so that the distance of the electrolyte entering the interior of the battery cell 20 can be shortened, and the electrolyte can be prevented from remaining on the hole wall of the first hole section k 1.

Of course, in other embodiments, part of the hole wall of the first hole section k1 may be attached to the outer wall of the pouring nozzle 400, and the pouring nozzle 400 may extend into the first hole section k 1.

Preferably, the liquid pouring port 403 of the liquid pouring nozzle 400 is disposed downward, so that the electrolyte can flow directly into the battery cell 20. Of course, the liquid pouring port 403 of the liquid pouring nozzle 400 may be disposed on the side wall of the liquid pouring nozzle 400 and opened toward the hole wall of the first hole section k1 or the hole wall of the second hole section k2, and at this time, a part of the electrolyte flows along the hole walls of the first hole section k1 and/or the second hole section k2 to enter the interior of the battery cell 20.

Preferably, the hole diameters of the second hole section k2 are equal everywhere, so that the electrolyte does not remain on the hole wall of the second hole section k2, and the installation of the first seal member 21b is more facilitated. Of course, the pore diameter of the second pore section k2 may be gradually increased from top to bottom, or may take other forms as long as the electrolyte is not easy to remain.

In some embodiments, with continued reference to fig. 5 and 7, the aperture diameter of the first hole segment k1 is gradually decreased from top to bottom, and the aperture diameter of the end of the second hole segment k2 connected to the first hole segment k1 is equal to or larger than the minimum aperture diameter of the first hole segment k 1.

The case where the pore diameter of the first pore section k1 gradually decreases from top to bottom includes: the hole wall of the first hole section k1 is an inclined wall with gradually reduced hole diameter, the hole wall of the first hole section k1 is an arc wall with gradually reduced hole diameter, and the like. When the aperture of the first hole section k1 is gradually reduced from top to bottom, a winding structure is not formed, and the electrolyte can smoothly flow downwards under the self-weight.

The minimum aperture diameter of the first hole section k1 is the aperture diameter of the end of the first hole section k1 connected to the second hole section k 2. The end of the second hole section k2 connected to the first hole section k1 is a first boundary end, when the aperture of the first boundary end is equal to the minimum aperture of the first hole section k1, that is, the two opposite ends of the second hole section k2 and the first hole section k1 are overlapped. When the aperture of the first boundary end is larger than the minimum aperture of the first hole section k1, the electrolyte flowing from the first hole section k1 to the second hole section k2 can directly flow toward the inside of the battery cell 20, so that the probability that the electrolyte flows along the hole wall of the second hole section k2 can be reduced, and the injection efficiency of the electrolyte can be improved.

Of course, the diameter of the first boundary end is usually set to be equal to the minimum diameter of the first hole section k1, so that the liquid filling hole k is formed with a large top and a small bottom, and the first sealing member 21b is more convenient to install.

At this time, when the aperture of the first hole section k1 is gradually reduced from top to bottom, a winding structure is not formed, the electrolyte can smoothly flow downward under the self weight, and the electrolyte flowing from the first hole section k1 to the second hole section k2 can directly flow toward the inside of the battery cell 20, so that the probability that the electrolyte flows along the hole wall of the second hole section k2 can be reduced, and the injection efficiency of the electrolyte can be improved.

The first seal 21b mentioned in the embodiment of the present application is a seal used for the primary sealing of the pour hole k, and the second seal 21c is a seal used for the secondary sealing of the pour hole k.

Fig. 9 is a schematic view of end cap 21a in a liquid-filled state according to other embodiments of the present application. In some embodiments, referring to fig. 9, the liquid injection hole k further includes a third hole segment k3, and the first hole segment k1 is connected between the third hole segment k3 and the second hole segment k 2. Wherein the aperture of the end of the third hole section k3 connected with the first hole section k1 is equal to or larger than the maximum aperture of the first hole section k 1.

The third hole segment k3 may be used as a hole segment for fitting the first seal member 21b, or may be used as a hole segment for fitting the second seal member 21c, and is not particularly limited. The end of the third bore section k3 connected to the first bore section k1 is a second interface end. The aperture of the second boundary end is larger than or equal to the maximum aperture of the first hole section k1, which is convenient for the use of the sealing nail and the liquid injection nozzle 400.

At this time, when the pouring hole k is sealed for the second time, the second sealing material 21c can be accommodated in the third hole section k3, and the second sealing material 21c can be prevented from being exposed outside the lid body a1, which is not beautiful and easily causes scratches to the outside.

Fig. 10 is a partial end view of cover a1 in some embodiments of the present application. In some embodiments, referring to fig. 10, an angle between the hole wall of the first hole section k1 and the thickness direction F of the cover a1 is a first angle α, wherein α is greater than or equal to 0 ° and less than or equal to 45 °. Specifically, the first included angle α may be 5 °, 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, and so on.

At this time, the hole wall of the first hole section k1 is an inclined straight wall, so that the processing is convenient. Meanwhile, the first included angle alpha is in the range of 0-45 degrees, the resistance of the hole wall of the first hole section k1 to the electrolyte is small, the electrolyte entering the first hole section k1 can conveniently and smoothly flow to the second hole section k2 under the self-weight, and the electrolyte is prevented from being stuck on the hole wall of the first hole section k 1.

As will be understood from FIG. 6, in order to fit the pouring nozzle 400 to the first hole section k1, the outer side wall of the part of the pouring nozzle 400 extending into the pouring hole k is also at an angle of α to the lid body a1 in the thickness direction F.

Referring to fig. 7 and 10, in some embodiments, the cover a1 includes a cover a11 and a liquid injection platform a12, the liquid injection platform a12 is protruded from a structural surface s of the cover a11, which is away from the inner portion of the battery cell 20, and the liquid injection hole k penetrates through the cover a11 and the liquid injection platform a 12.

In fig. 7 and 10, the interior of the battery cell 20 is located below the lid body a 1. The lid a11 is a structure of the lid a1 that forms a sealed space for accommodating the electrode assembly 23 with the case 22 of the battery cell 20, and may be plate-shaped or the like, and is not particularly limited. The side surface of the cover part a11 departing from the battery cell 20 is a structural surface s, the liquid injection platform a12 is a boss structure protruding on the structural surface s, and the liquid injection hole k simultaneously penetrates through the liquid injection platform a12 and the cover part a 11.

Understandably, the liquid pouring table a12 has an outer peripheral side wall w disposed continuously around the axial direction of the liquid pouring hole k and facing away from the liquid pouring hole k, and an end wall intersecting the outer peripheral side wall w and facing away from the interior of the battery cell 20. In actual operation, the second sealing member 21c can be covered on the end wall and is in sealing connection with the end wall so as to realize secondary sealing; further, the edge of the second sealing member 21c can be bent towards the cover part a11 and connected with the outer peripheral side wall w of the liquid injection platform a12 in a sealing manner, so that the sealing area and the sealing effect of the second sealing member 21c and the liquid injection platform a12 are increased; further, a welding position may be selected between the second seal member 21c and the outer peripheral side wall w of the liquid injection stage a12, so that the high temperature at the time of welding has less influence on the electrolyte.

At this time, the cap portion a11 is provided with the liquid injection platform a12 in a protruding manner, which not only can prolong the length of the liquid injection hole k, but also can increase the area of the matching surface 402 between the first sealing member 21b and the liquid injection hole k, thereby improving the effectiveness of primary sealing and the mounting stability of the first sealing member 21b, and simultaneously, the second sealing member 21c and the liquid injection platform a12 can be in bending contact to form a circuitous path, thereby improving the sealing reliability and the sealing effect of the liquid injection hole k.

With continued reference to FIGS. 7 and 10, in some embodiments, the peripheral side wall w of the pour deck a12 disposed around the axial direction of the pour hole k is configured with a crimp groove h recessed toward the pour hole k.

The outer peripheral side wall w of the pouring base a12 means a side wall that is continuously provided around the axial direction of the pouring hole k and that faces away from the pouring hole k, and it is understood that the pouring base a12 further includes an end wall that intersects with the outer peripheral side wall w.

The curling groove h is a groove sunken in the peripheral side wall w of the liquid injection hole k, can be continuously arranged around the axial direction of the liquid injection hole k, can also be arranged at intervals around the axial direction of the liquid injection hole k, and of course, the curling groove h can be only arranged one and is not arranged around the axial direction of the liquid injection hole k. The concave direction of the crimping groove h can be along the radial direction of the liquid injection hole k, and of course, can form a certain angle with the radial direction of the liquid injection hole k.

In actual operation, the second seal 21c covers the end wall of the pouring base a12, and after the edge thereof is at least partially bent toward the lid portion a11, it is bent in the radial direction of the pouring hole k and then inserted into the crimping groove h.

In this way, the second sealing member 21c can be sealingly connected to the groove wall of the crimping groove h, a part of the peripheral side wall w and the entire end wall, the sealing area of the liquid injection platform a12 and the second sealing member 21c is greatly increased, and the detour route formed by the crimping groove h, the peripheral side wall w and the end wall improves the sealing effect of the second sealing member 21 c. Further, the provision of the crimping groove h can also enhance the fixation between the second seal member 21c and the liquid injection table a 12.

Preferably, the second sealer 21c is sealed with the upper inner wall in the thickness direction F in the crimping groove h itself without contacting with the lower inner wall in the thickness direction F of the crimping groove h (i.e., the first wall surface hereinafter), and at this time, the second sealer 21c has a larger operating range at the time of crimping, and crimping of the second sealer 21c is easier.

In some embodiments, with continued reference to fig. 7 and 10, a side inner wall of the crimping groove h in the thickness direction F and disposed near the interior of the battery cell 20 is a first wall surface, and the first wall surface is flush with the structural surface s.

At this time, the curling groove h can be formed by the boss convexly arranged on the peripheral side wall w of the liquid injection platform a12 and the structural surface s together, and the forming of the curling groove h is more convenient without grooving and the like.

In some embodiments, with continued reference to fig. 7 and 10, the cover portion a11 is configured with an avoidance groove p recessed toward the inside of the battery cell 20, and the bottom surface of the avoidance groove p serves as a configuration surface s. Understandably, the avoiding groove p is located on the side of the cover portion a11 departing from the battery cell 20, the liquid injection groove is located in the avoiding groove p, and the relationship between the depth of the avoiding groove p and the height of the liquid injection platform a12 may be equal or different, and is not limited specifically.

The arrangement of the avoiding groove p can reduce the protruding height of the liquid injection platform a12 even not protruding, so that the influence of the liquid injection platform a12 on the outside can be reduced, and the liquid injection platform a12 can be prevented from being damaged by the outside. While the escape groove p can provide a large operation space when the second seal member 21c is bent as described below.

In some embodiments, with continued reference to fig. 10, the recess depth of the hemming groove h is a first dimension D1, the width of the hemming groove h in the thickness direction F is a second dimension D2, and the distance between the bottom of the hemming groove h and the side wall of the avoiding groove p disposed opposite to the bottom of the hemming groove h in the direction perpendicular to the thickness direction F is a third dimension D3. Wherein D1 is more than or equal to 0.5mm, D2 is more than or equal to 0.5mm, 2 is more than or equal to D1/D2 is more than or equal to 0.5, and D3 is more than or equal to 3D 1.

Understandably, the side wall of the avoiding groove p is arranged at an angle with the bottom surface thereof. Alternatively, D1=2mm, D2=1.5, D1/D2= 4/3. Optionally, D3=3D1=6 mm.

It has been proved through experiments that when the first dimension D1, the second dimension D2, and the third dimension D3 are within the above-mentioned ranges, a space for performing the crimping operation is large when the second sealing member 21c is crimped, thereby facilitating the crimping operation of the second sealing member 21 c.

In an alternative embodiment, with continued reference to fig. 7, a first hole section k1 is formed in the filling station a12, and a second hole section k2 is formed in the lid a 11. In practical operation, the first hole section k1 and the second hole section k2 can be processed and designed according to the height of the liquid injection platform a12 and the thickness of the cover part a11, so that the size of the liquid injection hole k is processed more accurately, and the size of the liquid injection hole k is designed more conveniently.

Of course, in other embodiments, the formation form of the first hole section k1 and the second hole section k2 is not limited to this, and for example, the first hole section k1 may be formed in the liquid injection stage a12, and the second hole section k2 may be formed in both the liquid injection stage a12 and the cap portion a 11. For another example, the second hole section k2 is formed in the cover portion a11, and the first hole section k1 is formed in both the liquid filling stage a12 and the cover portion a 11.

In some embodiments, referring to fig. 5, the end cap 21a further includes a blocking plate a2, and the blocking plate a2 is disposed on a side of the cap body a1 facing the inside of the battery cell 20 and blocks a flow path of the electrolyte flowing from the electrolyte injection hole k directly to the inside of the battery cell 20.

The baffle a2 is fixedly or integrally connected with the cover a1, and the cover a1 is used for ensuring that the baffle a2 has certain effect of resisting electrolyte impact. The baffle a2 blocks the flow path of the electrolyte flowing from the electrolyte injection hole k directly to the inside of the battery cell 20, that is, the electrolyte cannot flow from the electrolyte injection hole k directly to the battery cell 20 under the action of the baffle, but changes the flow direction when passing through the baffle a2 and then enters the inside of the battery cell 20.

Specifically, the baffle a2 is disposed opposite the pour hole k, and the orthographic projection of the pour hole k in the thickness direction F is within the orthographic projection range of the baffle. The electrolyte flowing out of the electrolyte injection hole k flows toward the baffle a2 under gravity, then changes its flow direction under the blockage of the baffle a2, and then enters the inside of the battery cell 20.

Meanwhile, when the buffer space f communicating the liquid injection hole k and the inside of the battery cell 20 is formed between the baffle a2 and the cover a1, and the outlet of the buffer space f is not aligned with the electrode assembly 23 inside the battery cell 20, the rapid flow of electrolyte can be prevented from directly impacting on the electrode assembly 23 to damage the electrode assembly 23.

In a preferred embodiment of the present application, referring to fig. 4 to 5, the end cap 21a includes a cover body a1, the cover body a1 has a liquid injection hole k penetrating through both sides of the cover body a1 in a thickness direction F, the liquid injection hole k includes a first hole section k1 and a second hole section k2 opened from top to bottom in the thickness direction F, two ends of the first hole section k1 and the second hole section k2 close to each other are overlapped, a hole diameter of the first hole section k1 is gradually reduced from top to bottom, and a hole diameter of the second hole section k2 is equal everywhere. The first hole section k1 is used for accommodating the pouring spout 400 and completely engages with the outer wall of the pouring spout 400 and is configured to form an overflow-preventing area above the pouring spout 403 in the pouring spout 400.

In a second aspect, the present application also provides an end cap assembly 21.

Fig. 11 is an assembly view of the cover a1 and the first sealing member 21b according to some embodiments of the present disclosure, and fig. 12 is an assembly view of the cover a1 and the first and

second sealing members

21b, 21c according to some embodiments of the present disclosure.

Referring to fig. 11 and 12, according to some embodiments of the present disclosure, an end cap assembly 21 is provided for a battery cell 20, where the end cap assembly 21 includes a first sealing member 21b, a second sealing member 21c, and an end cap 21a provided in any one of the above embodiments. The first sealing piece 21b is arranged in the liquid injection hole k and seals the first hole section k1 and the second hole section k2, and the second sealing piece 21c covers one side of the first sealing piece 21b, which is far away from the interior of the battery cell 20, and is connected with the cover body a1 in a sealing mode.

The end cap 21a is described in the above embodiments, and will not be described in detail here.

The first seal 21b is a member that can be inserted into the pour hole k to close the pour hole k, and seals the pour hole k once. The first sealing member 21b may completely block the injection hole k, i.e. the first sealing member 21b is hermetically connected with all hole walls of the injection hole k. The first sealing member 21b may partially close the pouring hole k, that is, the first sealing member 21b may be connected to a partial hole wall of the pouring hole k in a sealing manner to close the pouring hole k. The first seal 21b may be in the form of a sealing nail, a sealing post, a sealing plug, or the like. Alternatively, the first sealing member 21b is in interference sealing connection or threaded sealing connection with the liquid injection hole k. When the first sealing member 21b is screwed and sealed with the pouring hole k, the second hole section k2 may be internally provided with an internal thread screwed with the first sealing member 21 b. The first sealing member 21b may be a rubber member, such as rubber, silicone, etc., and is not limited in particular.

The second seal 21c may be a sealing sheet, a sealing plate, or the like, and may be connected to the lid body a1 in a sealing manner so as to cover the first seal 21b, thereby performing secondary sealing of the pouring hole k. Usually, the second seal 21c is made of a metal material (e.g., aluminum material) so as to be welded and sealed to the lid a 1. Of course, the second sealing member 21c is not limited to a metal material, and may be made of a plastic material when it is sealed by adhesion to the lid body a 1.

In the end cap assembly 21, the structure of the liquid injection hole k enables the electrolyte to flow into the battery cell 20 without obstruction, and the electrolyte basically does not remain in the liquid injection hole k, so that when the secondary sealing is performed on the liquid injection hole k, the occurrence of welding defects caused by the fact that the gasified electrolyte penetrates through a molten pool when the second sealing element 21c is welded is avoided, and the problem of reduction of the sealing reliability of the liquid injection hole k caused by the welding defects can be avoided.

In some embodiments, with continued reference to fig. 11 and 12, the cover a1 includes a lid a11 and a liquid injection platform a12, the liquid injection platform a12 is protruded from a structural surface s of the lid a11 facing away from the interior of the battery cell 20, and the liquid injection hole k passes through the lid a11 and the liquid injection hole k. The second sealing member 21c has a first sealing portion c1 and a second sealing portion c2 connected to each other, the first sealing portion c1 covers a side of the first sealing member 21b away from the inside of the battery cell 20, and the second sealing portion c2 is bent toward the inside of the battery cell 20 relative to the first sealing portion c1 and is connected to the outer peripheral side wall w of the liquid injection platform a12 in a sealing manner.

The terms of the cover portion a11, the liquid injection table a12, the outer peripheral side wall w of the liquid injection table a12, and the like, are described in detail in the above embodiments, and are not repeated herein.

The second sealing part c2 may be connected to the entire edge of the first sealing part c1 to be continuously provided around the first sealing part c1, or may be connected only to a portion of the edge of the first sealing part c1, and the second sealing part c2 may be plural, and a plurality of second sealing parts c2 may be spaced along the edge of the first sealing part c 1. The first sealing portion c1 and the second sealing portion c2 may be formed to form an included angle in advance, or may be formed to be bent and included angle in the field at the time of secondary sealing. The first sealing part c1 and the first sealing part c1 may be integrally connected.

After the first seal 21b is fitted into the pouring hole k, the second seal 21c is fitted to perform secondary sealing. Specifically, the first sealing portion c1 of the second sealing member 21c is first disposed on the side of the first sealing member 21b away from the interior of the battery cell 20, and at this time, the first sealing portion c1 may be attached to the end wall of the liquid injection platform a12 (for example, when the first sealing member 21b does not exceed the range of the liquid injection platform a 12), and the first sealing portion c1 may also be attached to the portion of the first sealing member 21b that exceeds the liquid injection platform a 12. Then, the second seal portion c2 of the second seal 21c is bent toward the inside of the battery cell 20 with respect to the first seal portion c1 until it comes into contact with the outer peripheral side wall w of the pour hole k. Finally, the second sealing member 21c is fixedly connected to the liquid injection stage a12 (e.g., welded, bonded, etc.).

In this way, the second seal 21c performs secondary sealing via the first seal portion c1 and the second seal portion c2, and the sealing area is large, and the sealing effect is good. Meanwhile, the first sealing part c1 and the second sealing part c2 are bent to form a circuitous sealing path, and the sealing effect is further improved.

In some embodiments, referring to FIG. 12, the peripheral side wall w of the pour deck a12 disposed around the axial direction of the pour hole k is configured with a bead groove h recessed toward the pour hole k. Wherein, second sealing portion c2 is including the first crimping section c21 and the second crimping section c22 that link to each other, and first sealing portion c1 is connected to first crimping section c21, and relative first sealing portion c1 towards the inside bending type setting of battery cell 20, first crimping section c21 and annotate liquid platform a 12's periphery lateral wall w sealing connection, and second crimping section c22 is relative first crimping section c21 towards annotating liquid hole k bending type setting, and sealing connection is in crimping groove h.

For the details of the crimping groove h, the above embodiments are not described herein.

The first crimping step c21 is bent toward the inside of the battery cell 20 with respect to the first sealing portion c1, and the second crimping step c22 is bent toward the liquid pouring hole k with respect to the first crimping step c 21. The first and second crimping sections c21 and c22 may be formed in a bent structure by direct molding or may be formed in a bent structure by in-situ crimping at the time of secondary sealing. The second crimping section c22 may be connected to a part of the edge of the first crimping section c21, or may be connected to the whole edge of the first crimping section c 21.

When the second sealing member 21c is crimped, after the first sealing portion c1 of the second sealing member 21c covers the end wall of the liquid injection platform a12 or the portion of the first sealing member 21b beyond the liquid injection platform a12, the first crimping section c21 is bent toward the inside of the battery cell 20, then the second crimping section c22 is bent toward the liquid injection hole k and extends into the crimping groove h, and finally the second sealing member 21c is fixed (e.g., welded, bonded) to the liquid injection platform a 12.

In the specific operation, the second sealing element 21c may be a sealing plate, the sealing plate is firstly covered on the end wall of the liquid injection platform a12 or the part of the first sealing element 21b exceeding the liquid injection platform a12, then the sealing plate is bent along the peripheral side wall w of the liquid injection platform a12, and then the end part of the sealing plate is bent towards the liquid injection hole k to the inside of the curling groove h. At this time, a sealing plate portion of the sealing plate which is covered on the end wall of the liquid injection stage a12 or a portion of the first seal 21b which exceeds the liquid injection stage a12 constitutes a first sealing portion c1, a portion of the sealing plate which is in contact with the outer peripheral side wall w of the liquid injection stage a12 forms a first crimping section c21, and a portion of the sealing plate which protrudes into the crimping groove h forms a second crimping section c 22.

At this time, the second sealing member 21c can be sealingly connected to the groove wall of the crimping groove h, a part of the outer peripheral side wall w and the entire end wall, the sealing area of the liquid injection stage a12 and the second sealing member 21c is greatly increased, and the detour route constituted by the crimping groove h, the outer peripheral side wall w and the end wall improves the sealing effect of the second sealing member 21 c. Moreover, the hook-shaped structure formed by the first sealing part c1, the first crimping section c21 and the second crimping section c22 can also strengthen the fixation between the second sealing part 21c and the liquid injection platform a 12.

Fig. 14 is a state diagram of the second seal member 21c according to some embodiments of the present application. In some embodiments, referring to fig. 12 and 14, second sealing member 21c includes a heat conductive layer c3 and a heat conductive layer c4 stacked together, a heat conductive layer c3 is located between heat conductive layer c4 and cover a1, and a heat conductive layer c3 is configured to be melted by heat to hermetically connect heat conductive layer c4 and cover a 1.

The hot melt layer c3 is a layer structure capable of melting when the ambient temperature rises and hardening and bonding the heat conductive layer c4 and the cover a1 when cooling, and the hot melt layer c3 may be a hot melt film layer formed of a thermoplastic bonding material having a lower melting temperature, such as polypropylene, ethylene-vinyl acetate copolymer (EVA), Polyamide (PA), polyolefin, polylactic acid, or the like.

The heat conductive layer c4 is a material layer with heat conductive property, and can be, but not limited to, a metal layer (e.g., aluminum layer, stainless steel layer), a ceramic layer (e.g., aluminum oxide, silicon oxide, etc.). Optionally, the thermally conductive layer c4 has some flexibility to facilitate bending.

After the second sealing member 21c is covered in place (if bending is needed, after the first crimping section c21 and the second crimping section c22 are formed by bending), the heat conducting layer c4 is heated, the heat of the heat conducting layer c4 is transferred to the hot melting layer c3, and the hot melting layer c3 is melted, the melted hot melting material has certain fluidity, can fill the space between the heat conducting layer c4 and the liquid injection table a12 (and/or the first sealing member 21 b), and realizes effective sealing and effective fixing of the second sealing member 21 c.

At this time, the heat conductive layer c4 and the liquid injection platform a12 (and/or the first sealing member 21 b) are bonded by the hot melt layer c3, and the hot melt temperature is much lower than the high temperature generated during welding, so that the vaporization of the electrolyte can be alleviated or even avoided, and the problem that the bonding strength is reduced and the sealing effect is affected due to the vaporized electrolyte penetrating through the hot melt layer c3 can be avoided.

Fig. 13 is a schematic view of the structure of the first sealing member 21b in some embodiments of the present application. In some embodiments, referring to fig. 11 and 13 together, the first sealing member 21b includes a main body portion b1 and a positioning portion b2 that are adjacent to each other in the thickness direction F, the main body portion b1 is sealingly fitted in the liquid injection hole k, and the positioning portion b2 is located outside the liquid injection hole k and overlaps the surface of the lid body a1 that faces away from the interior of the battery cell 20. The second seal member 21c is sealingly provided over the positioning portion b 2.

The main body portion b1 is the portion of the first seal member 21b that is located entirely inside the pour hole k, and is adapted to engage with and seal the pour hole k. The positioning portion b2 is a portion of the first seal that is located above the pour hole k and that extends beyond the pour hole k, and overlaps with the lid body a1 (specifically, may be an end wall of the pour).

When the first sealing member 21b is mounted, the main body b1 thereof first extends into the pouring hole k to close the pouring hole k, the positioning portion b2 gradually approaches the cover a1 (specifically, the end wall of the pouring liquid) as the main body b1 sinks, and when the positioning portion b2 overlaps with the cover a1 (specifically, the end wall of the pouring liquid), the main body b1 sinks to a position, and at this time, the first sealing member 21b is mounted in place.

The second sealing member 21c may be disposed to cover the positioning portion b2 in a sealing manner, and specifically, the first sealing portion c1 may be disposed to cover the positioning portion b 2.

In this way, whether the first sealing member 21b is mounted in place can be judged according to whether the positioning portion b2 overlaps the cover a1, so that the mounting of the first sealing member 21b is more convenient.

In some embodiments, with continued reference to fig. 11 and 13, the first sealing member 21b further includes a limiting portion b3 located outside the liquid injection hole k, the main body portion b1 is connected between the limiting portion b3 and the positioning portion b2, and the limiting portion b3 abuts against the surface of the cover body a1 facing the inside of the battery cell 20.

The stopper b3 is a portion of the first seal 21b that is located below the liquid inlet k, i.e., inside the battery cell 20, and has a dimension in the radial direction of the liquid inlet k that is larger than the liquid inlet k so as to abut against the inner surface of the lid body a1 (i.e., the surface of the lid body a1 facing the inside of the battery cell 20) after entering the inside of the battery cell 20.

Understandably, the stopper portion b3 is thin and has a certain flexibility/toughness to pass through the liquid injection hole k and to protrude into the interior of the battery cell 20. The stopper b3 is slightly larger than the pouring hole k in the radial direction of the pouring hole k so that the stopper b3 can easily protrude into the battery cell 20.

After the first sealing element 21b is mounted in place, the first sealing element 21b can be effectively prevented from falling off by limiting the first sealing element on the cover body a1 through the positioning part b2 and the limiting part b 3.

In a third aspect, the present application further provides a battery cell 20, which includes a casing 22, an electrode assembly 23, and the end cap assembly 21 in any of the above embodiments, where the casing 22 encloses to form a containing cavity with an opening, the electrode assembly 23 is contained in the containing cavity, and the end cap 21a covers the opening.

In a fourth aspect, the present application also provides a battery 100 including the battery cell 20 in the above-described embodiment.

In a fifth aspect, the present application further provides an electric device, which includes the battery 100 in the above embodiments, and the battery 100 is used for providing electric energy.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An end cap for a battery cell (20), the end cap (21 a) comprising:

the liquid injection device comprises a cover body (a 1) and a liquid injection hole (k), wherein the cover body (a 1) is provided with a liquid injection hole (k) penetrating through two sides of the cover body in the thickness direction (F), and the liquid injection hole (k) comprises a first hole section (k 1) and a second hole section (k 2) which are arranged from top to bottom in the thickness direction (F) of the cover body (a 1); the first hole section (k 1) and the second hole section (k 2) are communicated at two ends close to each other;

the first hole section (k 1) is used for accommodating the liquid injection nozzle (400), and at least part of hole wall is jointed with the outer wall of the liquid injection nozzle (400) to form an anti-overflow area; the anti-overflow area is positioned above the liquid injection port in the liquid injection nozzle (400).

2. An end cap according to claim 1, characterized in that the hole wall of the first hole section (k 1) completely fits the outer wall of the pouring spout (400), and the pouring opening of the pouring spout (400) extends into the second hole section (k 2).

3. The end cap of claim 1 or 2, wherein the aperture diameter of the first hole section (k 1) is gradually reduced from top to bottom, and the aperture diameter of the end of the second hole section (k 2) connected with the first hole section (k 1) is equal to or larger than the minimum aperture diameter of the first hole section (k 1).

4. The end cap of claim 3, wherein the pour spout (k) further comprises a third spout section (k 3), the first spout section (k 1) communicating between the third spout section (k 3) and the second spout section (k 2);

wherein the aperture of the end of the third bore section (k 3) connected to the first bore section (k 1) is equal to or larger than the maximum aperture of the first bore section (k 1).

5. The end cap of claim 3, wherein the angle between the aperture wall of the first aperture section (k 1) and the thickness direction (F) of the cover (a 1) is a first angle α, wherein 0 ° ≦ α ≦ 45 °.

6. The end cap of any one of claims 1 or 2, wherein the cover body (a 1) comprises a cover portion (a 11) and a filling station (a 12); the liquid injection platform (a 12) is arranged on a structural surface(s) of the cover part (a 11) which is separated from the inner part of the battery cell (20) in a protruding way, and the liquid injection hole (k) penetrates through the cover part (a 11) and the liquid injection platform (a 12).

7. An end cap according to claim 6, characterized in that the outer peripheral side wall of the liquid pouring platform (a 12) disposed around the axial direction of the liquid pouring hole (k) is configured with a bead groove (h) recessed toward the liquid pouring hole (k).

8. An end cap according to claim 7, characterized in that the cover part (a 11) is configured with an escape groove (p) recessed towards the inside of the battery cell (20), the bottom surface of the escape groove (p) being the configuration surface(s).

9. The end closure of claim 8, wherein the recess depth of the crimping groove (h) is a first dimension D1, the width of the crimping groove (h) in the thickness direction (F) is a second dimension D2, and the distance between the groove bottom of the crimping groove (h) and the side wall of the avoiding groove (p) disposed opposite the groove bottom of the crimping groove (h) in a direction perpendicular to the thickness direction (F) is a third dimension D3;

wherein D1 is more than or equal to 0.5mm, D2 is more than or equal to 0.5mm, 2 is more than or equal to D1/D2 is more than or equal to 0.5, and D3 is more than or equal to 3D 1.

10. The end cap according to claim 1 or 2, wherein the end cap (21 a) further comprises a baffle plate (a 2), and the baffle plate (a 2) is disposed on the side of the cover body (a 1) facing the inside of the battery cell (20) and blocks a flow path of the electrolyte flowing from the electrolyte injection hole (k) directly to the inside of the battery cell (20).

11. An end cap assembly for a battery cell (20), the end cap assembly comprising:

the end cap (21 a) of any of claims 1 to 10;

a first sealing member (21 b) which is arranged in the liquid injection hole (k) and blocks the first hole section (k 1) and the second hole section (k 2); and

and the second sealing piece (21 c) covers one side of the first sealing piece (21 b) departing from the interior of the battery unit (20) and is connected with the cover body (a 1) in a sealing way.

12. The end cap assembly of claim 11, wherein the cover (a 1) includes a cover portion (a 11) and a filling station (a 12); the liquid injection platform (a 12) is convexly arranged on a structural surface(s) of the cover part (a 11) which is separated from the inner part of the battery cell (20), and the liquid injection hole (k) penetrates through the cover part (a 11) and the liquid injection platform (a 12);

the second sealing piece (21 c) is provided with a first sealing part (c 1) and a second sealing part (c 2) which are connected, the first sealing part (c 1) covers one side, deviating from the inside of the battery cell (20), of the first sealing piece (21 b), and the second sealing part (c 2) is opposite to the first sealing part (c 1) and bends towards the inside of the battery cell (20) and is connected with the outer peripheral side wall (w) of the liquid injection platform (a 12) in a sealing mode.

13. The end cap assembly according to claim 12, wherein the liquid injection platform (a 12) is configured with a bead groove (h) recessed toward the liquid injection hole (k) on an outer peripheral side wall thereof disposed around the axial direction of the liquid injection hole (k);

the second sealing part (c 2) comprises a first crimping section (c 21) and a second crimping section (c 22), wherein the first crimping section (c 21) is connected with the first sealing part (c 1) and is opposite to the first sealing part (c 1) towards the inner part of the battery cell (20) in a bending mode, the first crimping section (c 21) is in sealing connection with the outer peripheral side wall (w) of the liquid injection platform (a 12), and the second crimping section (c 22) is opposite to the first crimping section (c 21) towards the liquid injection hole (k) in a bending mode and is in sealing connection with the crimping groove (h).

14. An end cap assembly according to any one of claims 11 to 13, wherein the second seal (21 c) comprises a thermally fusible layer (c 3) and a thermally conductive layer (c 4) arranged one above the other, the thermally fusible layer (c 3) being located between the thermally conductive layer (c 4) and the cover (a 1), the thermally fusible layer (c 3) being configured to be fusible by heat to sealingly connect the thermally conductive layer (c 4) and the cover (a 1).

15. The end cap assembly according to any one of claims 11 to 13, wherein the first seal member (21 b) includes a main body portion (b 1) and a positioning portion (b 2) that are adjacent in the thickness direction (F), the main body portion (b 1) is sealingly fitted into the liquid pouring hole (k), and the positioning portion (b 2) is located outside the liquid pouring hole (k) and overlaps a surface of the lid body (a 1) that faces away from the interior of the battery cell (20);

the second sealing member (21 c) is sealingly disposed over the positioning portion (b 2).

16. The end cap assembly according to claim 15, wherein the first sealing member (21 b) further comprises a stopper portion (b 3) located outside the liquid injection hole (k), the main body portion (b 1) is connected between the stopper portion (b 3) and the positioning portion (b 2), and the stopper portion (b 3) abuts against a surface of the cover body (a 1) facing the inside of the battery cell (20).

17. A battery cell, comprising:

a housing (22) enclosing a receiving cavity with an opening;

an electrode assembly (23) accommodated in the accommodation chamber; and

the end cap assembly of any one of claims 11 to 16, said end cap (21 a) covering said opening.

18. A battery comprising the cell of claim 17.

19. An electrical device comprising a battery as claimed in claim 18 for providing electrical energy.